JPS60133980A - Sensing welding method - Google Patents

Abstract

PURPOSE:To eliminate the need for teaching the sensing direction of a Y-shaped stylus and to simplify an operation by attaching said stylus to the side face of a welding torch, obtaining the vector in the direction of the welding torch and determining the sensing direction of the stylus. CONSTITUTION:A Y-shaped stylus is used. The tip of a welding wire W is matched with the corner part and the stylus is attached to the side face of a welding torch T in such a way that the axial direction thereof is made parallel with the torch and that the stylus is made freely extensible and contractable by means of a cylinder 3. The torch T is moved in the respective directions of the stylus and the positional deviation of a member P is detected by the short-circuit between side torch and the case attached to the number P. The vector in the direction of the torch T attached with stylus sensors 1, 2 is obtd. and the sensing direction for moving the sensors in the direction of the member to be welded is determined in the + or -45 deg. direction. Welding is accomplished while the welding is procressed while reversing from the final sensing point toward the first sensing point.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sensing welding method, and more particularly to a sensing welding method that can be applied to arc welding robots, automatic welding machines, sealant coating robots, and the like.

The following sensors are generally attached to arc welding robots for detecting welding lines.

α) Sensing with welding wire This method uses the welding wire itself, separates the welding power supply circuit before welding, connects another detection power supply, and connects the welding wire to the component by using the ground on one component side as a common line. This is a method of detecting electrically. In this case, the protruding lengths of the welding wires after welding are uneven, resulting in variations in detection stacking. For this reason, it is necessary to carry out work to make the protrusion length uniform (for example, cutting the wire, controlling the wire dispersion using the detection principle on a standard gauge, etc.) every time at each welding point, which is inefficient.

Furthermore, since there is only one welding wire, it is inside the corner.

Regardless of the butt groove, it is necessary to detect several points and calculate the corner or the center of the groove, which requires complicated software and increases robot cost.

(2) Sensing using a proximity switch, etc. There is a method of attaching a commercially available proximity switch to the welding torch and detecting the welding point in the same way as above before welding.There is also a method of automatically tracing the welding torch while sensing in real time during welding. .

In addition to the same drawbacks as (1), the former method has the large shape and size of the sensing device, which may cause a fatal problem that it cannot be applied to narrow spaces. Although the latter method does not cause any loss time due to sensing, the sensor itself is exposed to the high temperature and spatter atmosphere of the welding arc and is damaged, and the detection accuracy varies due to temperature drift, so it is not practical.

The present invention has been proposed in view of the above circumstances, and its purpose is to eliminate the drawbacks of the conventional method as described above,
Easy to temporarily attach in narrow spaces.

The present invention provides a low-cost sensing welding method.

The sensing welding method according to the present invention involves attaching all the Y-shaped stylus to the side of the welding torch, moving the spinning torch in each direction, and detecting the positional deviation of the member by short-circuiting the spinning torch with the ground attached to the member. Then, move the stylus sensor in the direction of the target member in the direction of +/-45" from the direction of the welding torch to which it is attached, and move from the last sensing point to the first sensing point. When welding while moving backwards towards The stylus is telescopically mounted parallel to the axial direction with an air cylinder, and the sensing direction of the stylus relative to the member is determined by software by vector calculation of the torch direction at the sensing teaching point.
This eliminates the need for teaching in the sensing direction as in the past, making the operation extremely simple.

An embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 is a diagram showing the configuration of an embodiment used to carry out the method of the present invention, Fig. 21 is a diagram showing an example of a member to be joined, and Fig. 3 is a diagram showing the sensing method of an embodiment of the present invention. FIG. 4 is a diagram showing the operation step path of the sensor.

T- is a welding torch attached to the wrist of a robot or automatic welder, and W is a welding wire.

I and 2 are stylus sensors, which are attached to the rod 4 of the air cylinder 3 attached to the side so as to be parallel to the axial direction of the welding torch T.
Attach it in a Y-shape to the tip of the

Both are insulated from each other and individually connected in parallel to the sensor activation relay contact 63 via the relay contacts 51 and 525 of the sensor control box 5, and the other end of the contact 63 is connected to the detection power supply 54, and the other end of the power supply 54 is connected to Connect to the member P to be welded. 55 is a short circuit detector provided in the same circuit, and is connected to a sensor short circuit detection relay 56. , 5Fq forward sensor activation relay 68 is an output switching relay to the stylus sensor 1.2, which is activated by the robot controller 6. Also, sensor short circuit detection relay 66
The contact signal is input to the robot controller 6. r is a solenoid valve for operating the sensor-mounted air cylinder S, and from its ports A and B, A of the air cylinder 3
, connect air piping to B. 31 to 11 in air cylinder B
B is a limit switch for detecting the backward position and forward position and is connected to the robot controller 6.

Figure 2 shows an example of the eastern part, which is box-shaped and consists of the bottom plate of the PI, the PI (D side plates (4 pieces), and the top plate of the P3 (opened flange!/), and the welding is Horizontal plate welding between bottom plate Pt and side plate P2 (outer l inner I'), vertical corner welding between side plates P2 [outer 2° inner 2'], upward fillet welding between side plate P2 and upper plate P3 [ Outside 3. Inside!] is required.The arrow in the figure indicates the direction of sensing operation.

The operation of the above embodiment of the present invention will be explained.

In FIGS. 3 and 4, (0) move the torch to the first teaching point of the tack welding location.

(1) Check whether sensing is specified as an operating condition, and if sensing is specified, follow the rules below.

(2) Operate solenoid pulp r, and air cylinder 3
The stylus sensor tml attached to the rod 4 is protruded.

(3) Check the forward signal with limit switch BIB.

(4) Sensor activation relay 5 W'ji (JN).

(5) Calculate the taught torch direction in this state as a vector from the posture of each axis of the robot to determine the sensing direction.

Button This sets the sensing order of the two stylus sensors to give priority to the direction of the side plate.

cl) Activate the relay 68 so that the output of the detection power supply 54 is output to the preceding stylus l.

(8) Torch direction (sensor direction) and 45″ direction [right angle 9
In the case of a fillet that intersects with 06, in the case of a groove, 1 of the groove angle. /21 standard] Torch 4A'ieigi
+ dross.

(9) When the stylus sensor l touches the member P and short-circuits,
The detection relay 56 is activated and a detection signal is input to the robot controller 6. This is the specified feed n that takes into account errors in the parts.
If a detection signal is not output even if sent to u1, it is assumed that a sensing error has occurred and an emergency stop is performed, and this is displayed.

(10) Stop moving the torch T when the detection signal is output.

(11) Back up the torch T by the length of the fingers and toes (O15-2.0). This is to prevent the stylus sensor l from being deformed by hitting a member during the line method operation.

(12) Switch the output to the stylus sensor 2.

(13) ) - torch direction (sensor direction) and -45° direction? I-Move.

04) When the stylus sensor 2 touches the member P, a detection signal is output. If there is no output, process in the same way as (9).

05) When there is a detection signal, the movement of the torch T is stopped.

06) Store the positional relationship of each axis of the robot at this point r as the welding end (crater) position.

(rI) Sensor power supply 54yrll L/-5:4te0
FF (,, Cuts the output to the stylus sensor 1.2.

08) Turn off the power to the solenoid pulp 2 and move the sensor backward.

(19) Check the reverse signal on the limit switch 31.

(2)) Torch T at the original position of the first teaching point
2 Return.

c! 1) Move the torch T to the second teaching point.

Thereafter, seven sensing operations are performed at the second teaching point according to α) to (15) above.

C22) Store the positional relationship of each axis of the robot with m2 teaching point) as the welding start position.

Below (17) to (turn off the output to the sensor according to 19).

Move back and end sensing.

(2) Feed the welding wire vlWt, turn on the welding power, and start the welding arc from the second teaching point.

(vague) Welding is carried out while traveling in the opposite direction to the welding end (crater) position at the first teaching point that was previously memorized.

(25) Cut the welding arc and stop at that position.

This completes the sequence from sensing to welding at one tack welding location, and moves on to the next step.

In view of the above, the method of the present invention provides the following excellent effects.

(1) The point where the two stylus sensors assembled in a Y shape touch the member (strictly speaking, the sensing movement that follows the preceding sensor packs the member by the amount of fingers and feet so as not to damage the member, but this (shorten the stylus by that amount), the torch direction will automatically match the corner. Therefore, complicated software equations such as calling sense positions and performing calculations can be avoided.

(2) Since the direction of sensing is automatically determined by vector calculation, it is convenient to use as it eliminates the need to tate each sensing step individually.

(3) Sensing operation steps (torch transfer i&!)
) is small in number and efficient.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of an embodiment used to carry out the method of the present invention, Fig. 2 is a diagram showing an example of a member to be welded, and Fig. 3 is a diagram showing the sensing method of an embodiment of the present invention. FIG. 4 is a diagram showing the operation step path of the sensor. 1.2...Stylus sensor, 6...Sensor control box, 6.
...Robot controller, 2...Solenoid valve, 55...Short circuit detector, P...Welded member, T...
・Welding torch, W...Welding wire.

Claims (1)

[Claims] A Y-shaped stylus is attached to the side of the welding torch, and the torch is moved in each direction to detect the positional shift of the member due to a short circuit between this and the ground attached to the member, and the stylus sensor is used as the target. The sensing direction for moving toward the member to be moved is in the direction of ±456 around the vector of the direction of the welding torch to which it is attached, and while moving in the opposite direction from the final sensing point to the first sensing point. Sensing welding method with all the features of welding.